Test that entering a TaskGroup more than once raises RuntimeError.

Simulate a case where the first bind() succeeds with an ephemeral port, the second bind() fails with EADDRINUSE, and verify that crea

Test for a situation where bind() always fails when other listeners are being bound to the same port as the first listener which was

Regression test for #370.

Test for #1130: Ensure that __truediv__ preserves the subclass type when called on a Path subclass.

This test does not do anything at run time, but since the test suite is also checked with a static type checker, it ensures that the memory o

Test that if the extra attribute getter raises KeyError, it won't be confused for a missing attribute.

Closely related to #695.

Test that a cancel scope only uncancels the host task as many times as it has cancelled that specific task, and won't count child tas

See also test_cancelled_scope_based_checkpoint.

Test that a unicode host name is encoded to ASCII using IDNA 2008 rather than the standard library's IDNA 2003 before being matched a

Test that there won't be any leftover Futures that don't get their exceptions retrieved. See https://github.com/encode/httpc

Test that wait_all_tasks_blocked() does not crash on an `asend()` object.

wait() should return once the process exits, rather than waiting for the piped stdout/stderr to close. Easiest triggered by a grandchild that

The total number of tokens available for borrowing. This is a read-write property. If the total number of tokens is increased, the